Objectification and quantification of the cognitive impairment from an existing HIV infection or HIV encephalopathy using magnetic resonance spectroscopy

Some patients with HIV develop dementia. Using in vivo proton nuclear magnetic resonance ((1)H-NMR) spectroscopy, it is possible to measure the metabolic changes noninvasively. In this study, it is of interest to answer the clinically relevant question of whether magnetic resonance spectroscopy is suitable for the diagnosis of HIV encephalopathy. In total, 14 HIV-positive patients were investigated by means of localized (1)H-NMR spectroscopy in the following locations: (1) the mid-parietal gray matter, (2) the parietal white matter (PWM), and (3) the frontal white matter. All patients had no other brain diseases, apart from the HIV encephalopathy. The clinical extent of HIV encephalopathy of each patient was investigated using the following tests: (1) an electroencephalogram, (2) a neurological examination and psychiatric assessment, and (3) a psychometrical test. The spectroscopic changes in the PWM were more pronounced than those in the cortex, and the myo-inositol/creatine (mI/Cr) signal showed a clear increase in the cortex. Overall, the mI/Cr ratio emerged as the most reliable and earliest parameter to indicate an HIV encephalopathy.

MRI in human immunodeficiency virus-associated cerebral vasculitis

Cerebral ischaemia caused by inflammatory vasculopathies has been described as complication of human immunodeficiency virus (HIV) infection. Imaging studies have shown ischaemic lesions and changes of the vascular lumen, but did not allow demonstration of abnormalities within the vessel wall itself. Two HIV-infected men presented with symptoms of a transient ischaemic attack. Initial MRI of the first showed no infarct; in the second two small lacunar lesions were detected. In both cases, multiplanar 3-mm slice contrast-enhanced T1-weighted images showed aneurysmal dilatation, with thickening and contrast enhancement of the wall of the internal carotid and middle cerebral (MCA) arteries. These findings were interpreted as indicating cerebral vasculitis. In the first patient the vasculopathy progressed to carotid artery occlusion, and he developed an infarct in the MCA territory, but then remained neurologically stable. In the second patient varicella zoster virus (VZV) infection was the probable cause of vasculitis. The clinical deficits and vasculitic MRI changes regressed with antiviral and immunosuppressive therapy.

Antiretroviral therapy (ART) from a neurological point of view. German Neuro-AIDS study group (DNAA)

Human Immunodeficiency virus can affect the peripheral (PNS) and central nervous system (CNS). In the ART / HAART era especially the CNS is said to be a virus reservoir so that neurologists have to be more and more integrated in therapy planning. Therefore the present paper describes neurological indications for ART, ART side effects involving the PNS and CNS and pharmacological interactions of ART with current neurological drug regimen.

Cryptococcus meningoencephalitis in AIDS: parenchymal and meningeal forms

CT and MRI in one case of Cryptococcus neoformans infection showed contrast-enhancing parenchymal lesions resembling granulomata or abscesses. After an initial phase without contrast enhancement, the full extent of the lesions was visible within 2 weeks of presentation. The enhancing masses were assumed to represent intracerebral cryptococcomas. Despite evidence of massive meningeal infection on cerebrospinal fluid (CSF) examination, no radiological signs of meningitis, invasion of the Virchow-Robin spaces or ventriculitis could be demonstrated. With antimycotic treatment the contrast enhancement disappeared and cystic, partly calcified lesions remained. Recurrence of meningeal infection without radiological correlates was apparent in this stage. In a second case of proven cryptococcus meningitis, dilation of Virchow-Robin spaces or cysts in the adjacent parenchyma were the main abnormalities on MRI. Enhancing masses were not detected. These cases may represent two different reactions of the immunocompromised hosts to infection with C. neoformans: widening of the perivascular spaces as a correlate of the more typical meningeal infection and enhancing parenchymal lesions as a sign of further invasion from the CSF spaces. Enhancement of cryptococcomas, indicating an inflammatory response in the surrounding brain, is not typical in patients with impairment of immune function.

[Metronome therapy in patients with Parkinson disease]

We studied 10 patients with Parkinson's disease and 12 patients with Parkinson-plus-syndrome, trying to improve patients' gait by application of various external rhythmic stimuli, including metronome stimulation (96 beats per minute = middle andante). The test course of the patients was 4 x 10 meters and 3 U-turns. The patients' gait quality under stimulation was compared with their free walk (velocity, number of steps, number of freezing episodes). Metronome stimulation significantly reduced the time and number of steps needed for the test course and also diminished the number of freezing episodes. March music stimulation was less effective and tactile stimulation (rhythmically tapping on the patient's shoulder) even produced negative results. The positive effect of metronome stimulation was also found, when the tests were not performed inside the hospital building, but outside in the hospital parc. Metronome stimulation was comparably effective in both patient sub-groups examined in this study (M. Parkinson, Parkinson-plus-syndrome) and seems to be an important additional help in the treatment of these patients. Electronical metronomes are not expensive, easy in handling, and portable. A theoretical explanation of metronome stimulation effectivity in patients with Parkinson's disease still needs to be elucidated.

Analysis of the systemic and intrathecal humoral immune response in progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a subacute viral infection of oligodendrocytes by JC virus occurring almost exclusively in immunocompromised patients. By use of partially purified recombinant VP1 as antigen, the IgG response was analyzed by a quantitative ELISA of paired cerebrospinal fluid (CSF) and serum samples. An intrathecal immune response to VP1, defined as an antibody-specificity index of CSF to serum antibody titers > or =1.5, was found in 76% of PML patients (47/62) but in only 3.2% of controls (5/155) (P < .001). Intra-blood-brain barrier synthesis of VP1-specific IgG antibodies is 76% sensitive and 96.8% specific for the diagnosis of PML. Furthermore, the excellent correlation (r = .985) between the plasma cell count in brain tissue and the humoral intrathecal immune response to VP1 in PML patients suggests a role for B cells in this disorder.

Detection of CSF-specific oligoclonal antibodies to recombinant JC virus VP1 in patients with progressive multifocal leukoencephalopathy

The intrathecal synthesis of antibodies against recombinant VP1, the major structural protein of JC virus (JCV), was studied in 18 patients with progressive multifocal leukoencephalopathy (PML) and in 31 patients with various neurological disorders. Two methods were used, the calculation of an antibody specific index (ASI) on one hand and an antigen-driven immunoblotting for the detection of oligoclonal antibodies on the other. Most PML patients displayed an elevated (> 1.5) ASI (78%) and anti-VP1 oligoclonal antibodies restricted to the cerebrospinal fluid (55%). Only two other patients (one case each of multiple sclerosis and of neuroborreliosis) also showed an intrathecal synthesis of anti-VP1 oligoclonal antibodies, likely as a result of a 'polyspecific' reaction within the central nervous system.

Paraneoplastic necrotising myelopathy in a case of AIDS with lymphoma

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[Isolated unilateral hypoglossal nerve paralysis in carotid dissection]

A 41-year-old man presented with a unilateral atrophy and paresis of his tongue which were not explained by any pathological finding in the brainstem or at the base of the skull. The diagnosis of right internal carotid artery dissection was suggested by magnetic resonance imaging and ultrasound examination and confirmed by arterial angiography. During anticoagulant therapy clinical recovery and angiographical improvement occurred.

Primary and secondary involvement of the CNS in HIV infection

The neurologic sequelae of human immunodeficiency virus (HIV) infection may be divided into primary (= HIV-induced) and secondary (= opportunistic infections and malignancies) manifestations. Our experience with 215 HIV-infected patients indicates that major clinical symptoms are due to a few, albeit important, neurologic diseases, although in a given patient rare and sometimes multiple complications have to be considered. The clinical features of acquired immunodeficiency syndrome (AIDS) encephalopathy and CNS toxoplasmosis that represent the major primary and secondary neurologic manifestations of AIDS are discussed in detail.

Immunoglobulin class- and subclass-specific HIV antibody detection in serum and CSF specimens by ELISA and Western blot

Twenty-four homosexual adult patients suffering from LAS or AIDS were investigated for immunoglobulin class- and IgG subclass-specific antibodies to human immunodeficiency virus (HIV) by the indirect ELISA and Western blot using monoclonal tracer antibodies. All patients revealed HIV-specific serum antibodies of IgG subclass 1, and half of them IgG3. Only two had IgG2 and one IgG4 antibodies. IgM-anti-HIV was present in a person who presented a sero-conversion in subsequent blood specimens. In twelve patients who developed signs of an ongoing encephalitis, cerebrospinal fluid specimens were also tested. HIV-specific IgG antibodies were usually restricted to the subclass 1. In two cases specific IgM was found to be present, although lacking in the blood specimens. By comparison with HSV antibody detection in blood and CSF, an intrathecal, possibly pathognomonic antibody formation to HIV could be confirmed, mainly directed to gp120, gp41 and p24.

Neurological complications in AIDS

Neurological complications in the acquired immunodeficiency syndrome (AIDS) are an important aspect of this new infectious disease and occur frequently. The existence of neurotropic variants of the human immunodeficiency virus (HIV), the causative agent of AIDS, is probable. Direct infection of the nervous system with HIV leads to a variety of HIV-induced neurological syndromes, the AIDS dementia complex being its most important representative. In addition, a large number of opportunistic infections and malignancies of the nervous system may complicate the disease. Major aspects of the clinical pictures, rational diagnostic approaches and treatment options of the most important sequels of HIV infection of the nervous system are discussed.

[Toxoplasmosis encephalitis in patients with AIDS]

Toxoplasmosis encephalitis developed in three male homosexuals with AIDS. Clinical symptoms of encephalitis began with a nonspecific organic mental syndrome. In two cases there developed late focal symptoms. There were light to moderately severe generalized EEG changes with additional focal signs. CSF findings and toxoplasmosis titres were not diagnostically altered. Computed tomography demonstrated multiple areas of decreased density in cortex and cerebellum. Administration of pyrimethamine and sulfamethoxydiazine to the three patients brought about clinical improvement within a few days and regression of abnormal CT changes within a few weeks of onset of treatment. One patient died after an encephalitis recurrence: autopsy demonstrated toxoplasma pseudocysts in immediate proximity to small necrotic foci in the brain. The possibility of toxoplasma encephalitis should be considered in AIDS patients who develop an organic mental syndrome. Often the diagnosis can only be made after response to a trial of toxoplasmosis treatment.